Conventionally, some image forming apparatuses, such as printers, are configured so as to have a recording-medium accommodating section (for example, a so-called sheet feed cassette and a sheet feed tray) for accommodating recording mediums such as sheets therein and convey the recording medium accommodated in the recording-medium accommodating section to an image forming position (a position at which an image is formed on a recording medium). Specifically, the image forming apparatuses generally has a configuration including a feeding roller for feeding the recording medium accommodated in the recording-medium accommodating section to a conveying path.
For example, Japanese Patent Application Publication No. 2000-85989 discloses an image forming apparatus in which a sheet accommodated in a sheet feed tray is fed by a sheet feeding roller (feeding roller) and a rotational shaft rotationally supporting the sheet feeding roller can be moved upward by a small distance. Specifically, both ends of the rotational shaft are inserted into elongated holes formed on supporting plates on both sides of the shaft, respectively. A solenoid having a plunger is attached to each of the supporting plates. The plungers of the solenoids are engaged with the rotational shaft. With such configuration, by turning on the solenoids, the rotational shaft can be pulled upward in the elongated holes to move the sheet feeding roller upward.